There are conventional game systems in which the player can perform a game operation by moving the controller device itself (e.g., see Patent Document 1). For example, a game system described in Patent Document 1 uses the image-capturing means of the controller device to capture an image of a marker device, and uses information obtained from the image captured (captured image) as a game input, thus allowing for an operation of moving the controller device itself. Specifically, since it is possible to determine the position or the attitude of the controller device from the position of the marker device in the captured image, the position of the marker device is obtained as the information described above to perform a game process in accordance with the position of the marker device in the game system. Note that in the game system, while the position at which the marker device is placed is arbitrary, the marker device is normally placed around the display device because it feels natural for the user to use the controller device while pointing it toward the screen on which the game image is displayed.